Blood

Question 1

What is the percent composition of whole blood?

Answer 1

Plasma - 55%
Formed elements - 45%

Question 2

What is the percent composition of plasma?

Answer 2

Water - 91%
Proteins - 7%
Albumins
Globulins
Fibrinogen
Prothrombin
Other solutes -2%
Ions, nutrients, waste
products, gases, regulatory
substances

Question 3

What is the percent composition of formed elements?

Answer 3

Erythrocytes - >99%
Platelets - <1%
Leukocytes - <1%

Question 4

What is the normal volume of blood?

Answer 4

Plasma - 2.6L
Formed elements - 2.4L
Whole blood - 4 to 6L
7% to 9% of total body weight

Question 5

Describe blood pH.

Answer 5

Blood is alkaline - pH 7.35 to pH 7.45
Acidosis occurs if blood pH decreases toward neutral.

Question 6

What percent of gases are transported in plasma?

Answer 6

About 1.5% of total oxygen
About 10% of total carbon dioxide

Question 7

List the white blood cells (leukocytes).

Answer 7

Neutrophils - 65-75%
Lymphocytes - 20-25%
Monocytes - 3-8%
Eosinophils - 2-5%
Basophils - 0.5-1%

Question 8

What are the blood cell counts of RBCs, WBCs, and platelets?

Answer 8

RBCs - 4.5-5 million/mm3 of blood
WBCs - 5000-10,000/mm3 of blood
Platelets - 300,000/mm3 of blood

Question 9

Explain hematopoiesis.

Answer 9

The formation of all new blood cells in the myeloid tissue (red bone marrow).
WBCs finish developing in the lymph nodes, thymus, and spleen.

Question 10

How long to blood cells live?

Answer 10

RBCs - about 4 months
WBCs (granular) - a few days
WBCs (agranular) - over 6 months

Question 11

Describe the structure of red blood cells.

Answer 11

-Tough, flexible plasma membrane (allowing RBCs to pass through small capillaries)
-Biconcave disc shape (large membrane surface area and reduced spinning as blood flows)
-Absence of nucleus and cytoplasmic organelles (provides more cellular space for hemoglobin; limits life span to about 120 days)

Question 12

What is the function of RBCs?

Answer 12

Transport of respiratory gases (oxygen and carbon dioxide)

Question 13

What is a CBC?

Answer 13

Complete blood cell count: battery of laboratory tests used to measure the amounts or levels of many blood constituents.

Question 14

What is a hematocrit (Hct) test?

Answer 14

Also called a packed cell volume (PCV) test.
Measures the percentage of RBCs in the whole blood.
Low RBCs - anemia
High RBCs - polycythemia

Question 15

Describe the structure and function of hemoglobin (Hb).

Answer 15

-Quaternary protein made up of four polypeptide chains (2 alpha, 2 beta), each with an oxygen-attracting heme group at the center.
-Iron, folate and B12 needed to manufacture Hb
-transport of respiratory gasses
-role in homeostasis of acid-base balance

Question 16

What is anemia?

Answer 16

The inability of blood to carry adequate oxygen to tissues due to:
1) inadequate RBC numbers
2) a deficiency of normal hemoglobin

Question 17

What is hemorrhagic anemia?

Answer 17

Decreased RBC numbers caused by blood loss (hemorrhage).

Question 18

What is aplastic anemia?

Answer 18

Decreased RBC numbers caused by destruction of blood-forming elements in bone marrow.

Question 19

What is pernicious anemia?

Answer 19

Lack of intrinsic factor in stomach reduces availability of vitamin B12 needed for RBC production.

Question 20

What is sickle cell anemia?

Answer 20

Inherited defective gene or genes produce an abnormal type of hemoglobin that is less able to carry oxygen and which often forms clumps of RBCs that block blood vessels.

Question 21

What is an antigen?

Answer 21

Substance than can activate immune system.

Question 22

What is an antibody?

Answer 22

Substance made by the body in response to stimulation by an antigen.

Question 23

What are the ABO blood types?

Answer 23

Type A blood - type A self-antigens in RBCs; anti-B type antibodies in plasma
Type B blood - type B self-antigens in RBCs; anti-A type antibodies in plasma
Type AB blood - type A and type B self-antigens in RBCs; no anti-A or anti-B antibodies in plasma
Type O blood - no type A or type B self antigens in RBCs; both anti-A and anti-B antibodies in plasma

Question 24

What is the Rh system of blood typing?

Answer 24

Rh positive blood - Rh factor antigen present in RBCs
Rh negative blood - no Rh factor present in RBCs

Question 25

What is Erythroblastosis Fetalis?

Answer 25

May occur when Rh-negative mother carries a second Rh-positive fetus; caused by mother's Rh antibodies reacting with the fetus's Rh-positive cells.

Question 26

What is the universal donor blood?

Answer 26

Type O-

Question 27

What is the universal recipient blood?

Answer 27

Type AB+

Question 28

What are the two types of WBCs?

Answer 28

Granulocytes - possess granules that stain. Agranulocytes - absence of stained granules.

Question 29

What is Leukopenia?

Answer 29

Abnormally low WBC count. -occurs infrequently -may occur with malfunction of blood-forming tissues or diseases affecting immune system (such as AIDS)

Question 30

What is Leukocytosis?

Answer 30

Abnormally high WBC count -frequent finding it bacterial infections -classic sign in blood cancers (leukemia)

Question 31

What is a Differential WBC count?

Answer 31

Component test in CBC; measures proportions of each type of WBC in blood sample.

Question 32

What are Neutrophils?

Answer 32

-granulocyte -most numerous type of phagocyte -numbers increase during bacterial infections

Question 33

What are Eosinophils?

Answer 33

-granulocyte -weak phagocyte -active against parasites and parasitic worms -involved in allergic reactions

Question 34

What are Basophils?

Answer 34

-granulocytes -related to mast cells in tissue spaces -secrete histamine (promotes inflammation) -secrete heparin (an anticoagulant)

Question 35

What are Monocytes?

Answer 35

-agranulocyte -largest leukocyte -aggressive phagocyte (capable of engulfing larger bacteria and cancer cells) -develop into much larger cells called macrophages after leaving blood to enter tissue spaces

Question 36

What are Lymphocytes?

Answer 36

-agranulocyte -B lymphocytes (B cells) involved in immunity against disease by secretion of antibodies -T lymphocytes (T cells) involved in direct attack on bacteria or cancer cells (not antibody production)

Question 37

What are platelets?

Answer 37

-Also called thrombocytes -Tiny cell fragments filled with clot-triggering chemical -play an essential role in blood clotting

Question 38

Describe the clotting process.

Answer 38

1) vasoconstriction of blood vessels 2) damage releases clotting factors that react with plasma factors to create prothrombin activator 3) platelets adhere to the break and form a "platelet plug" 4) prothrombin activator and calcium convert prothrombin to thrombin 5) thrombin reacts with fibrinogen to form fibrin 6) fibrin threads form a tangle to trap RBCs (and other formed elements) to produce a blood clot

Question 39

What is a thrombus?

Answer 39

A stationary blood clot

Question 40

What is an embolis?

Answer 40

A circulating blood clot

Question 41

What is tissue plasminogen activator (tPA)?

Answer 41

A drug used to dissolve already formed blood clots